This isn't good and I'm really worried about you... you really do need to leave the relationship and it won't be easy, but it'll be worth it. Someone else said to call Women's Aid, I'm not sure if there are any others but you definitely need to call someone and talk it through further, and he won't find it. If he regularly checks your phone, don't call from there, is there a home phone you could use?
I'm sorry, but this will only get worse if you leave it and it's hurting you..